We also document how we got the source code and keep our modifications out of the Qwt directory.

The latest version of qwt does have these warnings fixed. But the
latest version also has removed some deprecated printing functionality
which we are currently using. I gave a try at updating but it looked
fairly involved and over my level of understanding for that part of the
code. So pragmas for now. When someone does upgrade qwt the pragmas
will no longer be needed.

The latest version of qwt does have these warnings fixed. But the
latest version also has removed some deprecated printing functionality
which we are currently using. I gave a try at updating but it looked
fairly involved and over my level of understanding for that part of the
code. So pragmas for now. When someone does upgrade qwt the pragmas
will no longer be needed.

Put libraries into one libs directory under qgroundcontrol. Changed the neccessary files with references to those libraries.